// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/disk_cache/blockfile/mapped_file.h"

#include <memory>

#include "base/files/file_path.h"
#include "base/logging.h"
#include "net/disk_cache/disk_cache.h"

namespace disk_cache {

void* MappedFile::Init(const base::FilePath& name, size_t size)
{
    DCHECK(!init_);
    if (init_ || !File::Init(name))
        return NULL;

    buffer_ = NULL;
    init_ = true;
    section_ = CreateFileMapping(platform_file(), NULL, PAGE_READWRITE, 0,
        static_cast<DWORD>(size), NULL);
    if (!section_)
        return NULL;

    buffer_ = MapViewOfFile(section_, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, size);
    DCHECK(buffer_);
    view_size_ = size;

    // Make sure we detect hardware failures reading the headers.
    size_t temp_len = size ? size : 4096;
    std::unique_ptr<char[]> temp(new char[temp_len]);
    if (!Read(temp.get(), temp_len, 0))
        return NULL;

    return buffer_;
}

MappedFile::~MappedFile()
{
    if (!init_)
        return;

    if (buffer_) {
        BOOL ret = UnmapViewOfFile(buffer_);
        DCHECK(ret);
    }

    if (section_)
        CloseHandle(section_);
}

void MappedFile::Flush()
{
}

} // namespace disk_cache
